ThePiachu
commented
4 years ago It would definitely be an interesting production process. It would be fun to see some metal filings you generate by making items inefficiently that can be reprocessed back into full bars. Efficiency modules would reduce the waste generated as they also decrease the input material requirement.
trickenso
To expand on the principles introduced by wood pulp, crushed stone, tailings, etc., it would provide an additional environmental challenge and strategy if recipes produced waste products that then had to be stored, reprocessed and/or disposed of.
Butchery byproducts: butchering animals could produce skin scraps, bones or offal that could need to be be buried or burned, reprocessed into fertiliser, or other processes - scrap meat might form part of this process, but this currently seems to have obvious food uses, rather than requiring non-food reprocessing, storage and infrastructure. Butchery products might have an environmental effect as they decay - perhaps changing soil composition, or attracting wild animals, possibly causing danger of attack, or affecting animal populations. Butchery waste has historically been used in glue and gelatine manufacture, the tanning industry, and many other processes.
Waste from eating food: eating food could generate garbage/organic waste that would require disposal. This might affect where you choose to consume meals, and make inventory management a concern, especially with large workcrews performing calorie-intensive jobs, and would certainly add unavoidable garbage to player behaviour, as opposed to the current optional garbage. It might also affect which foods you decide to eat, if they produce different amounts and kinds of waste. This food waste might also might disrupt the ecosystem similarly to butchery waste.
This would be adding many additional layers of complexity, but additionally: perhaps to prepare food to be eaten outside a house, or not seated at a table you would need to process it into a packaged version of the food using paper/cardboard or similar, and packaging waste would be created when it is eaten. This would add some gameplay benefit to eating at a table in a house, and would also add additional cooking processes that might earn a premium in the market, while also producing an environmental impact in exchange for this added convenience.
Industrial processes could produce wood shavings/chips and metal swarf: industrial reclamation from metal machining processes, and use of sawdust/wood chips in wood pulp manufacturing or as fuel, or simply as a waste product would add some pushback from these production processes in terms of environmental/waste storage and processing effects. Waste glass in the form of cullet is often used in glassmaking to increase efficiency, and improve the working properties of the melt.
These are huge real-world industries, and the infrastructure to support them could require its own investment for this added efficiency, but it might never become economically viable in itself. Before this reprocessing is developed, the waste might provide a logistical challenge, and certain communities might decide not to invest in this at all, preferring to focus on the speed and convenience of direct processing. A waste disposal and reprocessing town might spring up around a site that was simply landfill for an industrial settlement.
Certain recipes that already produce byproducts could be finessed: recovered oil barrels might be a unique item 'reclaimed barrels' that need to be checked and maintained before they can be safely used again - for instance 10 recovered barrels could produce 9 regular barrels and some metal scrap. You might even have an alternate recipe for refilling 'reclaimed barrels' with oil directly that produces 'rusty oil barrel' or similar, which has a chance of leaking into the environment, or perhaps bursting into metal scrap and significant ground pollution directly. Much cheaper and more economically productive, but with potential for significant environmental fallout.
Reprocessing garbage: this could take many forms. Generic garbage could be reclaimed into a small amount of random scrap, or small amounts of all scrap, or produce unique waste that has its own disposal chain - or only be useful as fuel for an incinerator. This process might be infrastructure, power, and time-intensive - sorting, processing and reclaiming diverse elements. This is a developing industry in real life, and also adds a large amount of strategic interest. Directly recycling items that have lost their usefulness would also be strategically interesting, as mentioned here: https://github.com/StrangeLoopGames/EcoSuggestions/issues/1036#issuecomment-616001011
Not all reprocessing options might be available at first, and they might have different requirement, benefits and drawbacks. It might not always be the obvious choice to set up a complex recycling process, if you don't have significant production or waste stored to justify it, and all the research and infrastructure construction has to be diverted from other projects. This this might prove an interesting governance challenge - do you invest early so you're prepared, or wait until it's a more significant problem. Do you focus on more mining and manufacturing directly, to develop most quickly and efficiently, or spend research and infrastructure resources on recycling techniques that might not have as much of a direct economic benefit.
It's also possible these byproducts could be useful for other processes - scrap metal could be used to repair tools directly, perhaps, or it could be fed back into some kind of expanded maintenance and repair system like #1044 - cloth scraps being useful for patching worn clothing, perhaps; animal glue and sawdust could be used to repair wood furniture; slags, tailings and oil refining wastes like bitumen could be involved in road repair, etc.
Or it could all just be thrown into landfill for someone else to worry about :)